citronella grass Care (Cymbopogon nardus)

This species prefers bright, direct sun for strong, aromatic growth.

• Provide 6–8 hours of direct sunlight daily; morning sun with some light afternoon shade works well in hot summer climates.
• Plants tolerate light partial shade (3–4 hours sun), but clumps become looser, taller, and less fragrant with reduced light.
• In very intense summer sun, monitor for leaf scorch or bleaching, and consider filtered light during the hottest midday hours, especially in exposed sites.

Cymbopogon nardus prefers evenly moist but never waterlogged soil.

• Water when the top 3–5 cm of soil feels dry, using a deep soak rather than frequent light splashes to encourage deeper roots.
• Use well-drained, sandy or loamy soil; prolonged puddling, sour smell, or limp, yellowing leaves indicate overwatering and poor drainage.
• In hot, windy summer weather, expect more frequent watering; in cooler seasons reduce frequency, watching for curling, browning tips as a sign of underwatering.

This warm-season grass grows best in consistently mild to hot conditions.

• Optimal growth occurs around 70–90°F (21–32°C), which suits most late spring to early autumn conditions in warm and temperate regions.
• The plant is very frost-sensitive and typically damaged below 40°F (4–5°C), with serious injury or death near 32°F (0°C).
• Citronella grass tolerates short heat spikes up to about 100°F (38°C) if soil moisture is maintained, but prolonged extreme heat with dry soil leads to leaf browning and stress.

This grass handles a wide humidity range but benefits from moderately moist air.

• Target 40–60% humidity for steady growth, similar to typical indoor and outdoor summer conditions.
• It tolerates short dry spells, but very dry heated air can brown leaf tips and edges on citronella grass.
• If air is under 30%, group pots together, place trays with pebbles and water nearby, or move plants away from hot air vents.

This species prefers loose, fast-draining, moderately fertile soil.

• Use a mix of 50–60% loam or all-purpose potting mix with 20–30% coarse sand and 10–20% perlite to improve drainage and aeration.
• Aim for slightly acidic to neutral pH, around 6.0–7.0, which supports nutrient uptake for Cymbopogon nardus.
• In heavy clay ground, work in coarse sand and compost to create a crumbly, non-sticky structure that roots can easily penetrate.
• Avoid compacted, waterlogged, or peat-only mixes, which hold excess water and restrict oxygen around the root zone.

This species is well suited to container growing outdoors in warm seasons.

• Choose a deep, wide pot to support its clumping root system and to reduce the risk of the tall foliage tipping the container.
• Use a heavier material like ceramic or thick-walled plastic to improve stability in wind and reduce fast drying of the root zone.
• Raise the container slightly on feet or bricks so drainage holes stay clear and excess water can exit quickly after heavy rain or watering.

Cymbopogon nardus responds well to moderate feeding during its active growing season.

• Use a balanced liquid fertilizer (for example 10-10-10) at 1/2 strength every 4–6 weeks in spring and summer.
• Alternatively, apply a slow-release granular fertilizer once in early spring around the clump base.
• Incorporate mature compost into the top 2–3 in of soil annually to support nutrient levels.
• Stop feeding citronella grass in late summer and avoid fertilizing during winter dormancy.

Pruning Cymbopogon nardus helps maintain a dense, tidy clump and encourages fresh growth.

• Cut back dead, brown, or damaged leaves at the base at any time using clean, sharp shears.
• In late winter or very early spring, trim the entire clump down to 4–6 in to renew foliage.
• Remove overly crowded or leaning shoots to improve air circulation and overall plant shape.
• Disinfect tools before and after use to limit the spread of fungal or bacterial problems.

Container-grown Cymbopogon nardus benefits from periodic repotting or division to maintain vigor.

• Plan to repot or divide every 1–2 years in spring, when active growth resumes.
• Look for roots circling the pot, water running straight through, or slowed growth as signs it needs a larger container.
• Move into a pot 2–3 in wider with free-draining soil, keeping the root ball at the same depth.
• Water thoroughly after shifting and keep the plant shaded and evenly moist for 5–7 days to reduce transplant stress.

Cymbopogon nardus is most commonly propagated by division rather than seed.

• Divide mature clumps in spring or early summer when growth is strong and temperatures are warm.
• Lift the plant and split the root mass into sections, each with several healthy shoots and roots.
• Replant divisions at the original soil depth in loose, well-drained soil and water well.
• Keep divisions in bright light, 70–80°F, and consistently moist until new growth confirms establishment.

This warm-season grass is frost sensitive and needs winter protection in cool climates.

• In USDA zones 10–11, leave clumps in the ground and remove spent foliage in late winter.
• In cooler zones, dig and pot clumps before first frost, then overwinter indoors in bright light at 55–65°F.
• For plants left outside in mild climates, mulch the root zone with 5–8 cm of dry material to reduce freeze damage.